IMPELLER DEVICE FOR A SEWING MACHINE
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION This invention relates to a driving device for a sewing machine and, more particularly, to an improvement in a driving device that rotates a spindle in the sewing machine and at a low speed, by means of an engine. assistant.
DESCRIPTION OF THE RELATED ART A drive device for sewing machine of this type has been described by the Japanese Unexamined Utility Model Publication (OPI) number Sho. 53-17468 (the term "OPI", as used herein, means an "unexamined application"). In the driving device, the auxiliary motor is coupled to the spindle of the sewing machine. A pedal is connected directly by a rod to an operating lever corresponding to a clutch lever for the clutch motor. In the driving device for a conventional sewing machine, an auxiliary motor with spindle of the sewing machine is coupled. However, coupling the auxiliary motor directly with the spindle of the sewing machine does not allow proper control of the rotation speed. In order to overcome this difficulty, it is preferable to couple the auxiliary motor with a clutch motor.
SUMMARY OF THE INVENTION It is an object of the invention to provide a driving device for a sewing machine of the type wherein the driving arrow of the auxiliary motor is coupled with the driving arrow of the clutch motor, and wherein the rotation of the auxiliary motor it changes with the variation in the diameter of a pulley or the like, mounted on the impulse shaft of the clutch motor. Other objects and advantages of the invention will be pointed out partially in the description, or may be learned by practice of the invention. The objects and advantages of the invention can be achieved and obtained by means of the instrumentalities and combinations indicated in detail in the claims that come at the end. To obtain the objectives in accordance with the purpose of the invention, as incorporated and described herein, the transmission device for use with a sewing machine of the invention comprises: a pulse arrow of a clutch motor to rotate the arrow on the sewing machine at a first speed, coupling the driving arrow of a clutch motor operatively with a pulse arrow of an auxiliary motor to rotate the arrow on the sewing machine at a second speed, where the second speed is less than the first speed, and a variator element of the rotation, to vary a rotation speed output from the auxiliary motor. BRIEF DESCRIPTION OF THE DRAWINGS The appended drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the invention and, together with the invention, serve to explain the objectives, advantages, and principles of the invention. In the drawings: Figure 1 is a perspective view of a sewing machine equipped with an example of a sewing machine driving device, which constitutes a first embodiment of the invention. Figure 2 is an explanatory diagram, partly as a sectional diagram, showing a drive device for a sewing machine of the invention. Figure 3 is a perspective view showing one side of the transmission means in the sewing machine drive device of the invention. Figure 4 is a perspective view showing the other side of the transmission means shown in Figure 3. Figure 5 is a side view, partially as a section diagram, showing a clutch motor and an auxiliary motor. Figure 6A is a front view showing the connection of the clutch motor and the auxiliary motor. Figure 6B is an amplified diagram showing part of the one-way clutch. Figure 7 is an enlarged sectional view of the one-way clutch. Figure 8 is a block diagram showing the connection of the control means. Figure 9 is a flow chart for a description of a low speed sewing operation, with the sewing machine drive device of the invention. Figure 10 is a flowchart for a description of the operation of stopping the needle in a needle up position or in a lowered needle position. Figure 11 is a flowchart for a description of a wire cutting operation with the driving device of the sewing machine of the *
invention. Figure 12 is a perspective view showing a second embodiment of the invention, corresponding to Figure 3. Figure 13 is a perspective view showing a third embodiment of the invention, corresponding to Figure 3. Figure 14 is a perspective view showing a fourth embodiment of the invention, corresponding to Figure 3. Figure 15 is a sectional view showing the connection of the first and second operating levers in the fourth embodiment shown. in Figure 14.
DETAILED DESCRIPTION OF THE INVENTION Preferred embodiments will be described with reference to the accompanying drawings. Figures 1 and 2 show a driving device for a sewing machine constituting a first embodiment of the invention. The drive device, shown in Figures 1 and 2, has a clutch motor 1 and an auxiliary motor 2. The clutch motor 1 rotates the spindle 4 of the sewing machine 3 at a high speed to effect an operation 25 ordinary stitching. The auxiliary motor 2 rotates the spindle 4 of the sewing machine at low speed, for example, to stop the sewing needle in a desired position. The clutch motor 1 is mounted in the frame means 10 which is fixedly fastened to the lower surface of a sewing machine table 11, with known means, such as bolts 12. The auxiliary motor 2 is separated from the sewing machine 3 and the spindle 4. In the embodiment, the auxiliary motor 2 is mounted on the housing 20 of the clutch motor 1. More specifically, as shown in Figure 6A, the mounting board 20a is mounted on the motor housing 20 of clutch, and is fixedly secured to the box 20 by screws 20b which are coupled with threaded holes formed in a pulley cover. In order to fix the clutch motor 1 and the auxiliary motor 2 in the desired positions, the clutch motor 1 and auxiliary motor 2 housings have bolt holes and flanges that are formed when they are manufactured. By using bolt holes and flanges, the auxiliary motor 2 is fixed to the clutch motor 1. This method is advantageous in that the auxiliary motor 2 can be secured to the clutch motor 1, without modifying the motors, i.e. using holes and the tabs of the boxes. The clutch motor 1, as shown in Figure 2, comprises a rotor 30 which is the driving element of the engine 1; a brake shoe 31, fixed in the case 20 of the engine 1; and a clutch board 32, disposed between the rotor 30 and the brake shoe 31, such that it can move to contact the brake shoe 31 or the rotor 30. The clutch motor 1 has a driving position wherein the clutch board 31 is in contact with the rotor 30, a stop position where the clutch board 31 is in contact with the brake shoe 31 and a neutral position, where the clutch board 32 is not in contact with the rotor 30 or with the brake shoe 31. The clutch board 32 is mounted on an end portion of a clutch shaft 33 which serves as the transmission shaft of the clutch motor. The intermediate portion of the clutch shaft 33 is supported by means of suitable bearings 35 and 35 ', such that the clutch shaft is rotatable with respect to a carrier 34, but not axially movable. The carrier 34, as shown in Figure 5, is horizontal (when seen in Figure 5), slidable and supported by the bearings 35 and 35 ', fitted in the case 20 of the clutch motor 1, so that the clutch shaft 33 can be moved axially to take the three positions mentioned above, that is: the transmission position, the neutral position and the high position. The other end portion of the clutch shaft 33 extends through the carrier 34. A transmission pulley 40 is mounted on the other end portion of the clutch shaft 33., such that it is located adjacent to the carrier 34. In addition, a driven sprocket 41 is mounted via a one-way clutch 42, on the clutch shaft 33 such that it is located adjacent the drive pulley 40. An endless belt 44 is passed around the drive pulley 40 and a driven pulley 43, fixedly mounted on the spindle 4 of the sewing machine. The drive pulley 40 and the driven pulley 43 are V-shaped pulleys and the endless belt 44 is a V-band. In the preferred embodiment, the driven Catarina 41 is coupled through a synchronizing band 52 to a driving catarina 51 fixedly mounted in the transmission shaft 50 of the auxiliary motor 2. The driven catarina 41 is of an effective diameter greater than the driving catarina 51. This is advantageous since the impulse torque of the auxiliary motor clutch shaft can be increased, which contributes to an improvement in the cost of the operation. When the clutch motor 1 is in the driven position, the clutch plate 32 is in contact with the rotor 30 and the clutch shaft 33 is rotated in such a way that the spindle 4 of the sewing machine is rotated through the drive pulley 40 and the endless belt 44. The rotation of the auxiliary motor 2 is transmitted through the driving sprocket 51, the synchronizing band 52, the driven sprocket 41 and the single-way clutch 42, to rotate the clutch shaft 33. The rotation of the clutch shaft 33 is transmitted through the drive pulley 40, the endless belt 44, and the driven pulley 43, to rotate the spindle 4 of the sewing machine. In this operation, the transmission of the rotation of the clutch motor 1 to the driven sprocket 41 is prohibited by the one-way clutch 42. As described above, the one-way clutch 42 functions to prevent transmission of the clutch. rotation of the clutch motor 1 to the auxiliary motor 2. The one-way clutch 42 comprises a bushing 60 fitted on the clutch shaft 33 and an outer cylinder 61, rotatably equipped on the bushing 60. The driven catarina 41 is adjusted on the outer cylinder 61 and secured to the latter 61 by suitable means. As shown in Figure 6B, a plurality of triangular cuts 62 is formed in the outer periphery of the hub 60, at equal angular intervals, thereby defining triangular spaces, each of which includes a relatively narrow space 70 and a space relatively wide 71 between the inner cylindrical surface of the outer cylinder and the outer cylindrical surface of the hub 60. In each of the triangular spaces there is provided a roller 63, as shown in Figure 6B, and is urged by a spring 64. The drive pulley 40, the one-way clutch 42 and the driven Catarina 41 can be mounted on the clutch 43 without modification of the clutch 33. The drive pulley was previously fitted on the clutch shaft 33 with key means 42a, and is secured fixed to the clutch shaft 33 with a nut 42a and a screw 42b, formed on the end face of the clutch shaft. On the other hand, in the invention shown in Figure 7, a depression in the drive pulley 40, key means and a screw formed in the clutch shaft 33, with which a nut is connected, are used. The drive pulley 40 has the depression on the outer surface. The bushing 60 is mounted and slid over the clutch shaft 33, at the same time as it is coupled with the conventional key means in the clutch shaft 33, until it is adjusted in the depression of the drive pulley. The nut is inserted into the bushing 60 and threadedly engaged with the clutch shaft screw 33. The nut has a hexagonal head 42d to rotate.
When the driven Catarina 41 is rotated in the direction of the arrow of interrupted lines D, by the auxiliary motor 2, which is shown in Figure 6B, the outer cylinder 61 of the one-way clutch 42 is rotated in the same direction, of so that the rollers 63 are placed in the relatively narrow spaces 70, whereby the bushing 60 is rotated in the same direction as the outer cylinder 61. In such a manner, the clutch shaft 33, which is coupled through the key the bushing 60 is rotated with the bushing 60. The rotation of the driven Catarina 42 in the direction of the arrow D rotates the clutch shaft 33 in the same direction (indicated by the interrupted line). When the clutch shaft 33 is rotated by the clutch motor 1 in the direction indicated by the broken line in Figure 6B, the bushing 60 is rotated together with the clutch shaft 33, so that the rollers 63 are placed in the relatively wide spaces 71 against the elastic forces of the springs 64. Therefore, the rotation of the bushing is not transmitted to the outer cylinder 61 and the rotation of the clutch motor 1 is not transmitted to the driven Catarina 41. When the auxiliary motor 2 rotates , the clutch motor 1 adopts the neutral position. The clutch board 32 is free of the rotor 30 and the brake shoe 31 (described later in detail). A clutch lever 100 is provided to move the clutch plate 32 and the carrier 34 to allow the clutch motor to assume the transmission or impulse position, the neutral position or the impulse position. The clutch lever 10 (5) has a substantially L-shaped shape, as shown in Figures 2 and 5, having a vertical portion 101 and a horizontal portion 102 extending from the vertical portion 101. As shown in the Figure 5, the half of the vertical portion 101 is rotatably coupled by means of an arrow 103 to the housing 20 of the clutch motor 1. A coupling pin 104 is coupled to one end of the clutch lever 100, for example, the end of the vertical lever The coupling pin 104 has a head 105 which is uniformly fitted in a hole 34a formed in the carrier 34. At the other end of the clutch lever 100, the end of the horizontal portion 102 of the lever clutch 100 is moved in the direction of the arrow of solid lines 106, the carriage 34 and the clutch arrow 33 move to the left as seen in Figure 5, so that the clutch board
32 is moved towards the rotor 30. When, in contrast, the end of the horizontal portion 102 is moved in the direction of the arrow of interrupted lines 107, the carrier 34 and the clutch arrow 33 are moved to the right in the Figure 5, so that the clutch board 32 moves towards the brake shoe 31. Figure 5 shows the clutch board 32 coupled with the brake shoe 31. In Figures 2 and 5, the reference number 108 designates a return spring of the clutch lever that pushes the clutch lever 100 in such a manner that the clutch plate 32 is in contact with the brake shoe 31 by means of the clutch lever 100. The clutch lever 100 is engaged to the means of control. The control means operate, for example, to rotate the clutch motor 1 and the auxiliary motor to allow various sewing operations. In a preferred embodiment, the control means comprises transmission means 200 connected to the clutch lever 100 and an actuator 201 coupled to the transmission means 200. In the embodiment, the actuator 21 is a pedal. Similarly, as in the case of the pedal of an ordinary sewing machine, the middle portion of the pedal is rotatably supported by means of an arrow 2 Wave on the legs of the sewing machine. The pedal can be tilted by the foot of the operator to a plurality of positions inclined towards the front, a neutral position (releasing) and a plurality of positions inclined backwards. The term "tilted to the front", as used herein, is intended to mean that the foot presses the front portion of the pedal, which is located forward of the arrow 201a. Similarly, the term "backward bending", as used herein, is intended to mean that the foot presses the rear portion of the pedal that is located behind the arrow 201a. The pedal is operated as indicated by the lines interrupted in Figure 2, or as indicated by the arrow in Figure 3, in the front tilt and the backward tilt. The transmission means 200, comprises a first operating lever 301, coupled by means of a first coupling bar 300 to the actuator, that is, to the pedal 201; a second operating lever 303, coupled through a coupling lever 302 to the first operating lever 301; and a second coupling rod 304, through which the second operating lever is coupled to the clutch lever 100. The transmission means 200 is provided on one side of the mounting board 305, which is fixedly secured to the box of the clutch motor 1. As shown in Figure 3, one end portion of the first operating lever 301 is rotatably supported on the mounting board 305, through an arrow 306, and the other end portion is coupled through from a first coupling rod 300 to the pedal 201. An arrow 307 is secured to the middle of the first operation lever 301, near the other end of the operation lever 301. As shown in Figure 4, the arrow 307, thus secured, it is connected to an arched slot 308 formed in the mounting board 308. The second operating lever 303 is disposed substantially in parallel with the first operation lever 301, and its first p The extreme orifice is supported rotatably on the mounting board 305 by means of an arrow 309. Similarly, as in the case of the first operating lever 303, an arrow 310 is secured to the middle portion of the second operation lever 303, near at the other end of the second operating lever 303, and is connected to an arched slot 311, formed in the mounting board 305. When the pedal is tilted in the directions of the arrow of Figure 3, the first and second operating levers second 301 and 303 are tilted around arrows 306 and 309, in the direction of the arrows respectively. The first and second operating levers are coupled by means of a coupling mechanism, in such a way that they can move at a certain distance one with respect to the other. The coupling mechanism is designed as follows: an end portion of the coupling lever 302 is rotatably mounted on the arrow 312 formed on the second operation lever 303, and a slot 313 is formed on the other end portion on the lever coupling 302, such that the slot is longitudinally elongated from the coupling lever 302, and a pin 314 is secured to the first operating lever 301, and is coupled through the elongated slot formed 313. As shown in Figures 2 and 3, the first operating lever 301 is coupled to the second operating lever 303, through an elastic member which is a tension spring 315 in the preferred embodiment. An end portion of the second coupling rod 304 is connected to one end of the second operating lever 303. The other end portion of the second coupling rod 304 is connected to the horizontal portion 102 of the clutch lever 100. When, with the pin 314 of the lower end of the slot 313 of the coupling lever 302, the forward tilt is made to move the first coupling rod 300 down, the first operating lever 301 is tilted downward as seen in FIG. Figures 2 and 3, while the coupling lever 302 is moved downwards, as seen in Figure 2 and the second operating lever 303 is tilted downwards. When the second operating lever 303 is tilted in this manner, the second coupling rod 304 moves downward, so that the horizontal portion 102 is moved in the direction of the arrow of solid lines. As a result, the clutch board 32 is moved from the position shown in Figure 5 to the rotor 30, thereby moving it from the high position to the neutral position. As shown in Figure 1, a cover 350 is fixedly mounted on the mounting board 305 to cover the components mounted on the mounting board 305. The control means further comprises means 400 of auxiliary motor for starting the auxiliary motor 2.; clutch motor sewing means 500 for starting the clutch motor 1; setting means for the needle position 600, for fixing the needle in a desired position, and a thread cutter starting means 700, as well as a control circuit 800. In the preferred embodiment, the auxiliary motor switching device 400 includes an auxiliary motor start switch 401. The auxiliary motor start switch 401 is arranged such that its movable contact piece (or armature) 401a, is triggered by the movement of the first operation lever 301, such that the switch changes on and off. The auxiliary motor starting switch 401 is secured to the mounting board 305. The clutch motor switching means 500 comprises a synchronizer 501 which is mounted on the spindle of the sewing machine, in such a way that it is adjacent to the driven pulley. 43. The synchronizer 501 is capable of detecting the speed and needle position of the sewing machine. The needle position setting means 600, as shown in Figures 2 to 4, have a neutral actuator 601 and a first needle position switch 602. The starting means of the thread cutter 700 has a second needle position switch 603 and a safety actuator 604. The neutral actuator 601 and the first and second needle position switches 602 and 603, as well as the safety actuator 604 , are mounted on the side of the mounting board 605 which is opposite to the side where the transmission means 200 is provided. The neutral actuator 601 has a drive shaft 601a which is coupled to an end portion of a neutral lever 605. another end portion of the neutral lever 605 extends through a hole 606 formed in the mounting board 305, so as to be confronted with the upper edge of the second operation lever 303. The neutral lever 605 is rotatably supported on the mounting board 305, through an arrow 608. When the neutral actuator is started, that is, when its transmission shaft 601a is positioned as shown in FIG. In Figure 4, the other end portion of the neutral lever is rotated in such a manner as to push the second operation lever 303 downwards. In Figure 4, the reference number 609 designates a return spring mounted on the arrow 608 of the neutral lever 605. The end portion of the movable contact part (frame) 602a of the first needle position switch 602 is fixed with the upper edge of the first operating lever 301, as shown in Figure 3. The safety actuator 604 has a transmission shaft 604a. A safety pin 610 is secured to the transmission shaft 604a at the end and extends in a position substantially perpendicular to the longitudinal direction of the transmission shaft 604a. An end portion of the safety pin 610 extends through an elongated hole 611 formed in the mounting board 305 and, when necessary, moves under a projection 612 extending from the middle portion of the first operating lever 301. Therefore, when the transmission shaft 604a of the safety actuator 604, positioned as shown in Figure 4 is contracted, the safety pin 610 is caused to move under the projection 612 of the first operating lever 301 , so as to limit the downward tilting of the first operating lever 301. In Figure 4, the reference numeral 613 designates a return spring mounted on the transmission shaft 604a of the safety actuator 604. The starting means 700 of the thread cutter comprises a wire cutter solenoid 700a and a wire cutter sheet 701. The wire cutter solenoid 700a operates the wire cutter. The wire cutting blade 701, as shown in Figure 4, includes a substantially U-shaped lever 703, which is rotatably mounted on the mounting board 305, through an arrow 702. An end portion of the lever 703 is a first arm 705 extending through a hole 704 formed on the mounting board 305. The end portion of the first arm 705 is fixed with the upper edge of the first operating lever 301. The lever 703 further comprises a second arm 706 which is fixed with the movable contact 707 of the second switch 603 of needle position. Figure 8 is a block diagram showing the arrangement of the control circuit 800. The control circuit includes a CPU (central processor unit) 801, a motor driver 802, connected to the CPU 801 and an 803 solenoid driver. , connected to the CPU 801. The motor driver 802 is for controlling the auxiliary motor 2 and the solenoid driver 803 is for controlling the wire cutter solenoid. The CPU 801 is connected to the auxiliary motor start switch 401, to the first and second needle position switches 602 and 603, and to the other switches shown in Figure 8. The rotation variable means 805 varies the rotation of the auxiliary motor. On a sewing machine with a starter motor, in order to change the rotation of the spindle on the sewing machine, the clutch motor pulley is changed in diameter. In a sewing machine that uses the auxiliary motor to drive the transmission shaft of the clutch motor, the rotation of the spindle of the sewing machine driven by the auxiliary motor is changed. Therefore, the purpose of using rotation variator means is to electrically control the rotation of the auxiliary motor in accordance with the variation in the diameter of the clutch motor pulley. In a preferred embodiment, the rotation variator means comprises an immersion switch 806, as shown in Figure 8.; however, the control can be effected in accordance with the program of the CPU 801. The operation of the sewing machine drive device thus constructed will be described in conjunction with the operations of the sewing machine performed in response to pedal operations. When, as shown in Figures 2 and 5, the pedal is fixed in the first tilting position to the front, the front portion of the pedal in the neutral position is slightly depressed and the transmission means 200 is operated. As described beforehand, the first operating lever 301 is tilted downwardly by means of the first coupling rod 30, so that the horizontal portion 102 of the clutch lever 100 moves downward in the direction of the arrow of solid lines of Figure 5, with the help of the coupling lever 302, the second operating lever 303 and the second coupling rod 304. As a result, the clutch board 32 is moved from the first high position shown in Figure 5 to the neutral position. Therefore, the spindle 4 of the sewing machine can be turned by hand. In connection with this, it should be noted that the start switch 401 of the auxiliary motor is not connected. When the pedal is set in the second forward inclined position, the front portion of the pedal is further depressed, and the start switch 401 of the auxiliary motor is switched on, so that the auxiliary motor is driven to rotate the spindle 4 of the sewing machine, at low speed. Figure 9 is a flow chart for a description of a low speed sewing machine operation. When, after being fixed in the second position inclined towards the front, the pedal is fixed in the third position inclined towards the front, and the front portion of the pedal is further depressed, the transmission means 200 is operated in the same manner as it was operated in response to the first forward inclination of the pedal. As a result, the clutch board 32 is moved to the driving or driving position, so that it is pushed against the rotor 30. The rotation of the clutch motor is transmitted through the clutch shaft 33, the drive pulley 40. , the endless belt 44 and the driven pulley 43, to the spindle 4 of the sewing machine, so that the sewing machine is rotated at high speed. This rotation at high speed is used for an ordinary sewing operation. When the high speed exceeds a predetermined value, the synchronizer 501 detects it, to stop the rotation of the auxiliary motor. The auxiliary motor sets the rotation speed of the spindle to a predetermined value or less; for example, at approximately 300 rpm or less, for example, approximately 170 rpm. This will reduce the power consumption of the auxiliary motor and increase the service life of the machine. When the rear portion of the pedal, in the third forward inclined position is depressed, so that the pedal is fixed in the neutral position (or release position), the first coupling rod 30 is moved upward and the first lever of operation 301 is tilted upwards. In this operation, the upward tilting of the first operating lever 301 is not immediately transmitted to the second operating lever 303. This is due to the slot 313 formed in the other end portion of the coupling lever 302. When the upward movement from the first operation lever 301 becomes larger than the length of the slot 313, the second operation lever 303 moves up. When the first operation lever is moved along the slot of the coupling lever, the tension spring is pulled. When the second operating lever 303 is moved upward, the second coupling rod 304 is moved upward, so that the horizontal portion 102 of the clutch lever 100 is moved upwardly., as seen in Figure 5, in the direction of the arrow of interrupted lines, and the clutch board 32 is moved to the right by the spring force of the return spring 108 of the clutch lever, and is pushed against the brake shoe 31 (in the high position of the clutch motor). As a result, the clutch motor 1 is stopped. Under this condition, the sewing needle is in an unstable high position. When the pedal is fixed in the first backward inclined position, that is, when the rear portion of the pedal in the neutral position is depressed by the foot, the first tie rod 300 is moved upward and the first operating lever 301 is tilted up. As a result, the upper edge of the first operating lever 301 is brought into contact with the movable contact part 602a of the first needle position position switch 602, to connect the first needle position switch 602. At the same time , the synchronizer 501 detects the position of the needle and starts the neutral actuator 601 if the needle is in the needle up position. When the transmission shaft 601a of the neutral actuator 601 contracts, the neutral lever 605 is operated, so that the second operating lever 303 is tilted downwardly. In this operation, the downward tilting of the second operating lever 303 is not transmitted to the first operating lever 301 because the first operating lever 301 is moved along the groove 313 formed in the coupling lever 302 The downward tilting of the second operating lever 303 moves the second coupling rod 304 downwards, in such a way that the horizontal portion 102 of the clutch lever 100 is moved downwards, so that the clutch board 31 positioned as shown in Figure 5 is moved to the left to make the clutch motor take the neutral position. When the clutch motor takes the neutral position in the manner described above, the auxiliary motor 2 rotates the spindle 4 of the sewing machine at low speed. Next, the synchronizer 501 detects the position of the water and outputs a needle position signal down, when the needle is in the low needle position. The lower needle position signal deactivates (turns off) the neutral actuator 601 and the auxiliary motor 2. As a result, the neutral lever 605 is returned to the original position by the return spring 609, to release the second operation lever 303 , whereby the second operating lever 303 is tilted upwardly by the tension spring 315. When the second operating lever 303 is tilted in that manner, the second coupling rod 304 is moved upward to lift the horizontal portion 102. of the clutch lever 100, so that the clutch board 32 is moved to the right when seen in Figure 5, ie, it is pushed against the brake shoe 31. As described above, the elastic forces 108 return of the clutch lever and tension spring 315 are used to push the clutch board 32 against the brake shoe 31, to stop the auxiliary motor. The resilient forces of the return spring 108 of the clutch lever and the tension spring 315 are effective to bring the clutch board into contact with the brake shoe. In this way, the clutch shaft 33 and the spindle 4 of the sewing machine are fixed and the auxiliary motor 2 is stopped. When the pedal is in the first position tilted backward, the auxiliary motor rotates the spindle of the machine. sewing at low speed, and stops rotation when the sewing needle is in the low needle position. The needle can be stopped in the low needle position. In addition, the needle can be stopped in the high needle position in the same way with the aid of a switch 806, high or low needle position selector. When the end of the pedal of the second position tilted backward (corresponding to the rotation at high speed of the sewing machine) is pressed repeatedly, the pedal is fixed in the second position inclined backwards, the first operating lever 301 is tilted upwards through the first coupling rod 300, so that the first needle position switch 602 is connected and the first arm 705 of the thread trimmer 701 is raised, while the second arm 706 of the thread trimmer 701 is moved downward to press the moveable contact of the second needle position switch 603, and connect the second needle position switch 603. In relation with this, the control circuit 800 starts the safety actuator 604 and the transmission shaft 604a of the safety actuator 604 contracts against the spring force of the return spring 613, so that the safety pin 610 is forced to be underneath of the projection 612 of the first operating lever 301 to prevent the downward tilting of the first operating lever 301. This prevents the first The operating lever is moved downwards by carelessly pressing the front portion of the pedal and the return of the pedal allows the tension spring 315 to have a certain driving force, which can be used to push the clutch board against the brake shoe , in the manner described above. When the safety actuator 604 is started, the synchronizer 501 outputs the low needle position signal. In response to the low needle position signal, the neutral actuator 601 is started. The transmission shaft 601a contracts, so that the neutral lever 605 is urged to cause its end portion to tip the second lever downwardly. operation 303. In this operation, the downward tilting of the second operating lever 303 is not transmitted to the first operating lever 301 because the first operating lever 301 is moved along the groove 313 formed in the operating lever 303. coupling 302. The downward tilting of the second operating lever 303 moves the second coupling rod 304 downwards and, consequently, the horizontal portion 102 of the clutch lever 100 is moved downward. As a result, the clutch board 32 positioned as shown in Figure 5 is moved to the left, so that the clutch motor 1 assumes the neutral position. When the clutch motor 1 adopts the neutral position, the auxiliary motor 2 rotates the spindle 4 of the sewing machine at low speed. Then, the synchronizer 501 detects the needle position and outputs the low needle position signal when the needle is in the low needle position. In response to the low needle position signal, the control circuit starts the wire cutter solenoid to cut the wire with the wire cutter. The thread cutting operation can be carried out when the sewing machine is driven at low speed. After the thread cutting operation, the synchronizer 501 detects that the needle is in an up or high needle position, and outputs the high needle position signal. In response to the high needle position signal, the control circuit operates to stop the spindle 4 of the sewing machine, with the needle in the high position, de-energizes the wire cutter solenoid, for example, 20 milliseconds (controller time) and deactivates the security actuator 604, for example, for 60 milliseconds (time controller). Figure 10 is a flowchart for describing the stopping operation of the needle in the high needle position and in the low needle position. Figure 11 is a flow diagram for a description of the operation of cutting the yarn. In response to the needle position signal above, the neutral actuator 601 and the auxiliary motor 2 are deactivated. The transmission shaft 601a of the neutral actuator 601 is pushed outward by the spring force of the return spring 609. As a result, the neutral lever 605 is tilted so that the other end portion is moved away from the second operating lever 303. Consequently, the second operating lever 303 is tilted upwards by the elastic force of the tension spring 315, so that the horizontal portion 102 of the clutch lever 100 is raised through the second coupling rod 304. As described above, the clutch board 32 is moved to the right in Figure 5, so that it is pushed against the brake shoe 31. The spring forces of the return spring of the clutch lever 108 and the tension spring 315 contribute to the contact of the clutch board with the brake shoe. As a result, the auxiliary motor stops and the needle stops in the needle up position. The pedal is then operated to adopt the neutral position, so that the first operating lever 301 is tilted down, and the wire trimmer 701 is returned to its original position. Figure 12 shows a second embodiment of the invention. Figure 13 shows a third embodiment of the invention. Figures 14 and 15 show a fourth embodiment of the invention. In Figures 12 to 15, the parts correspond functionally to those that have already been described with reference to the first embodiment of the invention, are designated, consequently, with the same numbers or reference characters, with the character of (·).
The second modality shown in Figure 12 differs from the first modality for the following reasons. The first operating lever 301 is located below the second operating lever 303. The tension spring 315 'is placed on a bar 900. The lower end portion of the bar 900 is fixedly secured to the upper edge of the first operating lever 301 ', and the upper end portion' is loosely adjusted in the hole 901 formed in an ear extending from the lower edge of the second operation lever 303 '. The third modality shown in Figure 13 differs from the first modality for the following reasons. The first operating lever 301 'and the second operating lever 303' are rotatably mounted on one and the same supporting arrow 902. The fourth embodiment shown in Figures 14 and 15 differs from the first embodiment for the following reasons. The first operating lever 301 'is disposed on the second operating lever 303' in such a way that these levers extend vertically. Both the first and the second operating levers 301 'and 303' are supported on one end of a supporting lever 903, which is horizontally stretched. The other end of the support lever 903 is rotatably mounted on the mounting board 305 through an arrow 904. A top groove 905 and a bottom groove 906 are formed in both end portions of the operation lever 301. A hole 907 is formed in the lower end portion of the second operating lever 303 * such that it is adjacent the lower slot 906 of the first operating lever 301 '. Further, a slot 908 is formed in the second operating lever 303 'such that it is located above the hole 907 and is adjacent the upper slot 905 of the first operating lever 301'. A first bolt 909 is inserted in the upper slot 905 of the first operating lever 301 'and the slot 908 of the second operating lever 303'. A second bolt 910 is inserted into the lower slot 906 of the first operating lever 301 'and the hole 907 of the second operating lever 303 ·. The first and second nuts 909 and 910 thus inserted are opposite the nuts 911 and 912, respectively, for retaining the first and second operating levers such that they can be slidably slid with respect to each other. The first and second bolts 909 and 910 are coupled through the tension spring 315. The second, third and fourth modes operate in the same manner as the first mode. In the embodiments described above, the torque of the clutch motor is transmitted through the pulley assembly to the spindle of the sewing machine, and the torque of the auxiliary motor is transmitted through the assembly of the catarina to the spindle of the motor. sewing machine. However, the invention is not limited to that sense. For example, the pulley assembly and the Catarina assembly can be replaced by other means, such as, for example, gear assemblies. In the driving device according to the invention, the variator means of rotation is provided for the auxiliary motor, in such a way that the speed (rpm) of the auxiliary motor can be varied, proportionally to the variations in the diameter of the pulley of the motor. clutch motor. Accordingly, the spindle speed of the sewing machine can be set to a value suitable for a given sewing operation. The above description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and modifications can be made that may be acquired from the practice of the invention. The modalities were selected and described in order to explain the principles of the technique for using the invention in different modalities and with different modifications that are suitable for the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.